• Transactions of the Korean hydrogen and new energy society
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• v.21 no.1
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• pp.26-34
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• 2010

The electrocatalystic prperties of Pt-Co and Pt-Ni with heteropolyacids (HPAs) entrapped in covalently cross-linked sulfonated poly(ether ether ketone) (CL-SPEEK)/HPA membranes were investigated for water electrolysis. The HP As, including molybdophosphoric acid (MoPA), and tungstophosphoric acid (TPA) were both used as membrane additives and electrocatalysts. The membrane electrode assembly (MEA) was prepared by a nonequilibrium impregnation-reduction (I-R) method. $Pt(NH_3)_4Cl_2$, $NiCl_2$ and $CoCl_2$ as electrocatalytic materials and $NaBH_4$ as reducing agent were used. I order to enhance electrocatalytic activity, the catalyst layer prepared above was electrodeposited (Dep) with HP A. Surface morphologies and physico-chemical properties of MEA were investigated by means of SEM, EDX and XRD. The electrocatalytic properties of composite membranes such as the cell voltage and coulombic charge in CV were in the order of magnitude: CL-SPEEK/MoPA40 (wt%) > CL-SPEEK/TPA30 > Nafion117. In the optimum cell applications for water electrolysis, the cell voltage of Pt/CL-SPEEK-MoPA40/Pt-Co (Dep-MoPA) and Pt/CL-SPEEK-TPA30/Pt-Co (Dep-TPA) was 1.75 Vat $80^{\circ}C$ and $1\;A/cm^2$ and voltage efficiency was 87.1%. Also, the observed activity of Pt-Co (84:16 atomic ratio by EDX) is a little higher than that of Pt-Ni (86: 14). The current density peak of electrodeposited electrodes were better a little than those of unactivated electrodes based on the same membranes.

• Journal of the Korean Magnetics Society
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• v.14 no.5
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• pp.180-185
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• 2004

The electromagnetic properties and microstructures of the basic composition of (Ni$\sub$0.2/Cu$\sub$0.1/Zn$\sub$0.2/)$\sub$0.5/ (Fe$_2$O$_3$)$\sub$0.5/ were invested by changing of SO$_4$, Cl and NO$_3$ series. We were prepared by coprecipitation method and sintered at temperatures 950$^{\circ}C$, 1150$^{\circ}C$, l350$^{\circ}C$, respectively. When sintering at temperature 950$^{\circ}C$, Cl and NO$_3$ series became perfection sintering. On the other hand, SO$_4$ series showed perfection sintering at temperature 1150$^{\circ}C$. According to particle size analysis result, higher magnetic permeability and magnetization value were observed by Cl series than SO$_4$ or NO$_3$ series.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2203-2207
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• 2009

Chemical equilbria of nickel chloride in HCl solution at $25\;{^{\circ}C}$ were analyzed by considering chemical equilibria, mass and charge balance equations. The activity coefficients of solutes were calculated by using Bromley equation. The necessary thermodynamic properties, such as the equilibrium constant for the formation of Ni$Cl^+$ at zero ionic strength and interaction parameter, were evaluated by applying Bromley equation to the stability constant data reported in the literature. It was found that most nickel exists as $Ni^{2+}$ in HCl solution up to 5 molality HCl. The pH values of Ni$Cl_2-HCl-H_2O$ system at $25\;{^{\circ}C}$ calculated in this study agreed well with the pH values measured by employing pH meter.

• Journal of Powder Materials
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• v.6 no.4
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• pp.294-300
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• 1999

This study was carried out to investigate the possibility whether Metal Injection Molding (MIM) process could be applied to 95wt.%W-3.5wt.%Ni-1.5wt.%Fe heavy alloy in order to obtain an intricate shape. Methylcellulose was used in the injection molding for binder. $FeCl_2-4H_2O$ was added in solvent substituting Fe powder and $FeCl_2$ was doped on W-Ni premixed powder. When $FeCl_2-4H_2O$ was added in solvent, the binder separation occurred for injection molding so that the matrix content was changed. Such problem was solved when $FeCl_2$ was doped. In this study. the debinding process did not affect residual carbon content. The sintered microsouctures as addition methods of Fe element and the sintering temperature from $1420^{\circ}C$ to $1470^{\circ}C$, which are around the temperature of liquid phase formation, were observed.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.285-291
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• 2004

As a part of assessment of the structural material for the molten salt handling system, corrosion behavior of Inconel 718, X-750, Haynes 75 and Haynes 263 alloys in the molten salt of LiCl-Li$_2$O-O$_2$was investigated in the range of temperature; $650^{\circ}C$, time; 24~168h, $Li_2O$; 3wt%, mixed gas; Ar~10%$O_2$. In the molten salt of LiCl-$Li_2O-O_2$, the order corrosion rate was Haynes 263 ＜ Haynes 75 ＜ Inconel X-750 ＜ Inconel 718. Haynes 263 alloy showed the highest corrosion resistance among the examined alloys. Corrosion products of alloys were as fellows: Haynes 75: $Cr_2O_4$, $NiFe_2O_4$, $LiNiO_2$, $Li_2NiFe_2O_4$, Inconel 718; $Cr_2O_4$, $NiFe_2O_4$, Haynes 263; $Li(Ni,Co)O_2$, $NiCr_2O_4$, $LiTiO_2$, Inconel X-750; $Cr_2O_3$, $NiFe_2O_4$,$FeNi_3$, (Al,Nb,Ti)$O_2$. Haynes 263 showed local corrosion behavior and Haynes 75, Inconel 718 and Inconel X-750 showed uniform corrosion behavior.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.985-991
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• 1999

Corrosion behaviors of Incoloy 800H, KSA(Kaeri Superalloy)-6, Inconel 600 and Hastelloy C-276 in molten salts were investigated in the temperature range of 650 ~ $850^{\circ}C$. Due to $\textrm{Li}_{2}\textrm{O}$-induced basic fluxing mechanism, the corrosion rates of the alloys in mixed molten salt of LiC1-$\textrm{Li}_{2}\textrm{O}$ were significantly higher than those in molten salt of LiCl. In the mixed molten salt, Fe-base alloys showed higher corrosion resistance than the Ni-base alloys. and Hastelloy C-276 with high Mo and W contents exhibited the highest corrosion rate among the examined alloys. The single layer of $\textrm{LiCrO}_{2}$ was formed in molten salt of LiCl and two phase structure of a scale consisted of oxides and Ni was formed in the mixed molten salt.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.683-692
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• 2009

The synthesis of a novel series of nickel(II) complexes with new ligands derived from hydrazones of isoniazid have been reported in present work. The complexes have general compositions [$Ni(L)_2X_2$] or $[Ni(L)_3](ClO_4)_2$ {L = N-isonicotinamido-furfuraldimine (INH-FFL), N-isonicotinamido-3',4',5'-trimethoxybenzaldimine (INH-TMB) or N-isonicotinamido-cinnamalidene (INH-CIN) and X = $Cl^-$, ${NO_3}^-$, $ NCS^-$ or $CH_3COO^-$}. The ligands hydrazones behave as neutral bidentates (N and O donor) through the carbonyl oxygen and azomethine nitrogen. The new complexes with octahedral geometry have been characterized by elemental analysis, molecular weight determinations, magnetic susceptibility/moment, thermogravimetric, electrochemical and spectroscopic studies viz. infrared and electronic spectra. On the basis of conductivity measurements in nitrobenzene ($PhNO_2$) solution the [$Ni(L)_2X_2$] and $[Ni(L)_3](ClO_4)_2$ complexes have been found to be non-electrolytes and 1:2 electrolytes, respectively. Thermal properties have also been investigated, which support the geometry of the complexes. Antibacterial and antifungal properties of nickel(II) complexes and few standard drugs have also been examined and it has been observed that the complexes have moderate antibacterial activities.

• Corrosion Science and Technology
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• v.10 no.5
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• pp.180-188
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• 2011

In the present study, denting corrosion experiments were performed as a function of crevice gap size (50, 100 and 200 ${\mu}m$) in a solution containing 3,500 ppm NaCl + 0.2 M $CuCl_2$ (pH = 3 adjusted by HCl). The effects of chloride ion concentrations (3, 3,500 and 35,000 ppm as NaCl) were also outlined with two different crevice gap sizes (100, 200 ${\mu}m$). In addition, the effect of NiB on the denting corrosion was also investigated in a solution of 35,000 ppm NaCl + 0.2 M $CuCl_2$ (pH = 3 adjusted by HCl). The results showed that denting rate increased with the increasing crevice gap size at an initial stage and became nearly constant afterwards. As the concentration of chloride ion increased, the denting rate also increased. However, the addition of a NiB powder of 4 g/L in to the acid-chloride solution was observed to suppress the denting rate significantly.

• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.428-435
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• 1988

Some nickel(Ⅱ) and palladium(Ⅱ) complexes of the ambidentate ligands derived from condensation of the isonitrosoacetylacetone and various diamines, $Ni(IAA)_2-en$, $Ni(IAA)_2-pn$, $Ni(IAA)_2-tn$, $Pd(IAA)_2-en$, PdCl(IAA)-pn, and $Pd(IAA)_2$-tn, where (IAA)$_2$-en, $(IAA)_2$-tn, and (IAA)-pn represent N,N'-enthylenbis(isonitrosoacetylacetone imine), N,N'-propylenebis(isonitrosoacetylacetone imine), N,N'-trimethylenebis(isonitrosoacetylacetone imine) and N-(2-aminopropyl)isonitrosoacetylacetone imine, respectively, have been prepared. The nickel(Ⅱ) and palladium(Ⅱ) complexes were characterized on the bases of the elemental analysis, IR, NMR, and electronic spectra. It is suggested that a isonitroso group of (IAA)$_2$-en or (IAA)$_2$-tn coordinates to the metal ion through the nitrogen atom to form five-membered ring, while the other isonitroso group of (IAA)$_2$-en or (IAA)$_2$-tn coordinates to the metal ion through the oxygen atom to form six membered ring in square-planar complexes of Ni(IAA)$_2$-tn and Pd(IAA)$_2$-en. And two isonitroso groups of (IAA)$_2$-en, (IAA)$_2$-pn, or (IAA)$_2$-tn coordinate to the metal ion through the nitrogen atom to form five-membered rings in square-planar complexes of Ni(IAA)$_2$-en, Ni(IAA)$_2$-pn, and Pd(IAA)$_2$-tn. On the other hand, square-planar PdCl(IAA)-pn is formed by the reaction of propylenediamine with a isonitrosoacetylacetone in the presence of palladium(Ⅱ)ion.

• 한국전기화학회:학술대회논문집
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• 2004.04a
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• pp.35-35
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• 2004